We have also shown a marked enrichment of IFNγ-producing T cells that express high levels of the chemokine receptors CCR5 and CXCR3 in the JIA joint (3) and that chemokines (CCL5, CCL3, and CXCL10) that attract Th1 cells are enriched in JIA synovial fluid (33). Here, IFNG is linked to juvenile idiopathic arthritis.